From nobody Mon Feb 9 16:16:57 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8E255EB64D8 for ; Thu, 22 Jun 2023 06:54:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230353AbjFVGyg (ORCPT ); Thu, 22 Jun 2023 02:54:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56048 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230327AbjFVGy3 (ORCPT ); Thu, 22 Jun 2023 02:54:29 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 43BCD1BF7; Wed, 21 Jun 2023 23:54:24 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C45FA1042; Wed, 21 Jun 2023 23:55:07 -0700 (PDT) Received: from a077893.blr.arm.com (unknown [10.162.40.20]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id AB4373F59C; Wed, 21 Jun 2023 23:54:18 -0700 (PDT) From: Anshuman Khandual To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, will@kernel.org, catalin.marinas@arm.com, mark.rutland@arm.com Cc: Anshuman Khandual , Mark Brown , James Clark , Rob Herring , Marc Zyngier , Suzuki Poulose , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , linux-perf-users@vger.kernel.org Subject: [PATCH V13 03/10] arm64/perf: Add branch stack support in struct arm_pmu Date: Thu, 22 Jun 2023 12:23:44 +0530 Message-Id: <20230622065351.1092893-4-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230622065351.1092893-1-anshuman.khandual@arm.com> References: <20230622065351.1092893-1-anshuman.khandual@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" This updates 'struct arm_pmu' for branch stack sampling support being added later. This adds an element 'reg_trbidr' to capture BRBE attribute details. These updates here will help in tracking any branch stack sampling support. This also enables perf branch stack sampling event on all 'struct arm pmu', supporting the feature but after removing the current gate that blocks such events unconditionally in armpmu_event_init(). Instead a quick probe can be initiated via arm_pmu->has_branch_stack to ascertain the support. Cc: Catalin Marinas Cc: Will Deacon Cc: Mark Rutland Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Tested-by: James Clark Signed-off-by: Anshuman Khandual --- drivers/perf/arm_pmu.c | 3 +-- include/linux/perf/arm_pmu.h | 9 ++++++++- 2 files changed, 9 insertions(+), 3 deletions(-) diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c index aada47e3b126..d9ffe9e56e74 100644 --- a/drivers/perf/arm_pmu.c +++ b/drivers/perf/arm_pmu.c @@ -510,8 +510,7 @@ static int armpmu_event_init(struct perf_event *event) !cpumask_test_cpu(event->cpu, &armpmu->supported_cpus)) return -ENOENT; =20 - /* does not support taken branch sampling */ - if (has_branch_stack(event)) + if (has_branch_stack(event) && !armpmu->has_branch_stack) return -EOPNOTSUPP; =20 return __hw_perf_event_init(event); diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h index f7fbd162ca4c..ba4204bdcebf 100644 --- a/include/linux/perf/arm_pmu.h +++ b/include/linux/perf/arm_pmu.h @@ -102,7 +102,9 @@ struct arm_pmu { int (*map_event)(struct perf_event *event); void (*sched_task)(struct perf_event_pmu_context *pmu_ctx, bool sched_in= ); int num_events; - bool secure_access; /* 32-bit ARM only */ + unsigned int secure_access : 1, /* 32-bit ARM only */ + has_branch_stack: 1, /* 64-bit ARM only */ + reserved : 30; #define ARMV8_PMUV3_MAX_COMMON_EVENTS 0x40 DECLARE_BITMAP(pmceid_bitmap, ARMV8_PMUV3_MAX_COMMON_EVENTS); #define ARMV8_PMUV3_EXT_COMMON_EVENT_BASE 0x4000 @@ -118,6 +120,11 @@ struct arm_pmu { =20 /* Only to be used by ACPI probing code */ unsigned long acpi_cpuid; + + /* Implementation specific attributes */ +#ifdef CONFIG_ARM64_BRBE + u64 reg_brbidr; +#endif }; =20 #define to_arm_pmu(p) (container_of(p, struct arm_pmu, pmu)) --=20 2.25.1